Abstract: A short-circuit sense circuit and a power supply according to an exemplary embodiment of the present invention use an auxiliary voltage, which is a both-end voltage of an auxiliary coil coupled with a predetermined turn ratio to a secondary side coil coupled to an output voltage. After termination of a start-up period, the short-circuit sense circuit samples a sense voltage, which is a voltage of a node between a first sense resistor and a second sense resistor coupled in series to both ends of the auxiliary coils and determines whether a short-circuit occurs according to a short-circuit sense signal that depends on a result of comparison between the sampled voltage and a predetermined reference voltage.

Abstract: A voltage regulator includes an operational amplifier that compares a feedback voltage that is proportional to an output voltage and a predetermined reference voltage that corresponds to a desired output voltage. The operational amplifier controls the conduction state of an output transistor according to the comparison. A detecting circuit monitors the operating state of the operational amplifier, and in the case that the operational amplifier is not operating, outputs a signal which causes the output transistor to be placed in a non-conductive state.

Abstract: A renewable energy, utility size electric power system is provided with a high voltage, renewable energy harvesting network connected by a direct current link to a centralized grid synchronized multiphase regulated current source inverter system. The harvesting network includes distributed renewable energy power optimizers and transmitters that control delivery of renewable energy to the grid synchronized multiphase regulated current source inverter system. A visual immersion monitoring and control system can be provided for a three-dimensional, visually-oriented, virtual reality display, command and control environment.

Abstract: A flyback-based power conversion apparatus and a power conversion method thereof are provided. By switching first and second detection switches disposed in a control chip and coupled to a multi-function pin of the control chip at different timings, the present invention applies a collocation of a voltage-current detection auxiliary circuit and a current detection circuit at a certain timing to execute a detection of the AC input voltage received by a flyback power conversion circuit, and the present invention applies a collocation of the auxiliary voltage-current detection circuit, an over temperature protection unit and an over voltage protection unit at another timing to execute detections of an over temperature protection and an over voltage protection. As the result, a single multi-function detection pin of the control pin is corresponding to a plurality of related function detections, so as to reduce the production cost of manufacturing the control chip.

Abstract: Exemplary embodiments are directed to a method for operating a converter, wherein the converter includes a plurality of bridge branches having one or more switching cells connected in series. Each bridge branch connects one of a plurality of inputs to one of a plurality of outputs of the converter. The method includes monitoring each of the switching cells in order to determine a fault. If a fault is identified in one of the switching cells, triggering one of the triggering elements for short-circuiting switching cell connections if the fault identified in the switching cell is not followed by identification of a fault in a further one of the switching cells within a predetermined period of time.

Abstract: A system includes a current measurement unit, an overload timer, and a processing unit. The current measuring unit measures current through a power transistor, and the overload timer measures an overload time associated with the measured current. The processing unit receives a user-specified overload time setting or a user-specified overload amperage setting associated with a protection device connected in series with a load, receives a temperature measurement of a component associated with the power transistor or a measurement of overload time associated with the current, wherein the power transistor supplies the current to the load and the protection device, and selectively turns off the power transistor based on the measured temperature, the measured current through the power transistor, and the user-specified overload amperage setting or based on the measured temperature, the measured overload time, and the user-specified overload time.

Abstract: A circuit (1) is described for detecting a reverse current condition of a DCDC converter (2). This circuit uses a simple logic gate such as an AND gate to sense the voltage on a determined node (7) of the DCDC converter, and the propagation of the gated signal (27) is controlled using the timing control signals SW1 and SW2 of the DCDC converter, together with delay cells (16 and 17), to ensure that the positive or negative state of the sensed voltage at said node (7) is propagated cleanly through the logic gate (18), the flip-flop or latch circuit (19) and the up-down counter (29) to the output timing control circuit (25). The up-down counter is incremented or decremented in dependence on the presence or absence of a reverse current condition at said node, and the count value (24) of the up-down counter determines the duration of the on-period of the second-phase timing control signal SW2.

Abstract: A switching power supply converts an input voltage to a predetermined output voltage by controlling a switching device. The switching power supply includes a controller and a current detector. The controller controls the switching device. The current detector detects electric current flowing through the switching device. The controller starts a forced-OFF action to forcedly turn OFF the switching device when the current detected by the current detector exceeds a predetermined threshold and then ends the forced-OFF action at a start of a predetermined switching period.

Abstract: This relates to detecting unwanted couplings between a protected terminal and an adjacent terminal of an IC controller of a power supply. The voltages across adjacent terminals are monitored. If the voltage difference between the terminals falls below a minimum threshold for greater than a first duration of time, an internal current source injects current into one of the terminals. If, within a second duration of time, the injected current pulls the voltage of the injected terminal to a voltage that causes the voltage difference between the terminals to be above the minimum threshold, it may be determined that a transient fault has occurred and been cleared or falsely detected. If, however, the injected current does not pull the voltage of the injected terminal to a voltage that causes the voltage between the adjacent terminals to be above the minimum threshold, the fault condition is confirmed and switching is disabled.

Abstract: A loop controller includes an error amplifier configured to receive an output of a controlled process and further configured to receive a reference input; and an asymmetric compensator. The asymmetric compensator includes a high pass filter configured to receive an amplified version of the reference input and output a filtered reference; and an asymmetric impedance configured to receive an amplified version of the filtered reference and output a compensation signal. The error amplifier is further configured to sum the compensation signal and the output of the controlled process, and provide an error signal based on a difference between the sum and the reference input. The compensation signal includes a first gain for a rising transition of the controlled process output and a second gain for a falling transition of the controlled process output.

Abstract: The present application relates to a cascaded H-Bridge medium voltage drive, a power cell, and a bypass module thereof, wherein the bypass module is configured for bypassing a major circuit module of the power cell, while the major circuit module comprises a fuse, a rectifier, a bus capacitor and an H-Bridge inverter, two points led from the H-Bridge inverter being configured as a first output end and a second output end; a bypass circuit comprises a first bridge arm and a second bridge arm; a point led from the first bridge arm is configured as a first input end of the bypass circuit, a point led from the second bridge arm is configured as a second input end of the bypass circuit, and the first input end is electrically connected with the first output end, the second input end is electrically connected with the second output end.

Abstract: A power supply current monitoring device is used for a load drive apparatus with two systems to drive a load. Each system includes a drive circuit connected in parallel with a battery, a capacitor connected between the battery and the drive circuit, and a relay connected between the drive circuit and a point at which power of the battery is divided between the systems. When overcurrent is detected once in one system, a repetitive monitoring process is performed. The monitoring process finally determines that the overcurrent actually occurs when a predetermined condition is satisfied after repeating a monitoring cycle in which an overcurrent time during which the overcurrent continues after the relay is turned ON is accumulated. The condition is satisfied when the monitoring cycle in which the overcurrent time reaches a predetermined threshold is repeated a predetermined consecutive number of times.

Abstract: A surge protection circuit for a circuit having a rectification module. The surge protection circuit includes a first diode, a second diode, a capacitor and a discharge device. The anode of the first diode is connected to a first input of the rectification module, and the anode of the second diode is connected to a second input of the rectification module. The cathodes of the first and second diodes are both connected to the first plate of the capacitor. The second plate of the capacitor is connected to the negative output of the rectification module. The capacitor is configured such that it is consistently charged to substantially the peak value of a supply voltage during normal operation between surge events.

Abstract: The present invention relates to a thermal shutdown unit, a switch controller including the same, and a method controlling a thermal shutdown protection operation. The present invention determines the operation state of an SMPS to vary a reference temperature for controlling a thermal shutdown protection operation according to an operation state of the SMPS.

Abstract: According to one embodiment, there is provided a power supply circuit including a direct-current voltage source, a bridge circuit, a transformer, and a rectifying and smoothing circuit. The bridge circuit includes at least one switching element and converts a direct-current voltage supplied from the direct-current voltage source into an alternating-current voltage according to ON and OFF of the switching element. The transformer includes a primary winding wire connected to the bridge circuit and a secondary winding wire magnetically coupled to the primary winding wire. The rectifying and smoothing circuit converts the alternating-current voltage output from the secondary winding wire into a direct-current output voltage and supplies the direct-current output voltage to a direct-current load. The bridge circuit includes a capacitor connected between the primary winding wire and a terminal on a low potential side of the direct-current voltage source.

Abstract: A regulating circuit includes a first comparator configured to control a turning on and a turning off of a first transistor based on a first comparison a reference voltage to a feedback voltage. The first transistor is coupled between an output node and a first voltage supply. A second comparator is configured to control a turning on and a turning off of a second transistor based on a second comparison of the reference voltage to the feedback voltage. The second transistor is coupled to the output node. A high-impedance circuit is coupled in series with the second transistor such that the high-impedance block is disposed between the second transistor and a second power supply. The high-impedance circuit is configured to generate a constant current between the output node and the second voltage supply when the second transistor is turned on.

Abstract: A field device for determining and/or monitoring a physical or chemical, process variable in automation technology. The field device comprises: at least one microcontroller; a supply unit of limited capacity as primary voltage supply; and a detection circuit, which signals the microcontroller of a failure of the supply unit so early by means of a detection signal that sufficient time is available to take suitable safety measures, in order to avoid loss of data. The detection circuit is so embodied that a reference voltage required for detection of a voltage decline of the supply unit has an almost constant offset from the supply voltage of the supply unit and adjusts to the supply voltage, until the detection circuit, in the case of an abrupt subceeding of the reference voltage, or an abrupt voltage decline of the supply voltage, sends a detection signal to the microcontroller.

Abstract: A power distribution system comprises a power supply, a plurality of loads connected to one of the power supply and ground and a plurality of pulse generators, each pulse generator connected to each of the plurality of loads, configured to generate pulses to connect the plurality of loads to the other one of the power supply and ground at predetermined frequencies.

Abstract: Provided is a voltage regulator including an overcurrent protection circuit in which an output voltage-output current characteristic exhibits an optimal fold-back characteristic even when an overcurrent state is detected. The overcurrent protection circuit includes a control circuit for generating a current in accordance with an output voltage, and controls a gate of an output transistor with use of a current obtained by subtracting the current from a sense current flowing in accordance with an output current.

Abstract: There is provided an output circuit for supplying an output current to a load coupled to an output terminal in response to an input signal. The output circuit includes an output transistor for supplying the output current to the output terminal, an output-drive circuit for driving the output transistor, a constant-current limiting circuit for generating a current control signal for limiting the output current to a predetermined current value, and a control circuit for implementing a control such that the output current is controlled on the basis of the current control signal if a voltage at the output terminal is at a predetermined voltage, or less after the input signal is supplied while the output transistor is driven by the output-drive circuit if the voltage at the output terminal is in excess of the predetermined voltage.

Abstract: An apparatus for performing communication control includes a control module implemented with at least one integrated circuit (IC) whose package includes a plurality of sets of terminals, each set of the plurality of sets of terminals corresponding to one of a plurality of sub-modules of the control module, and within the sets of terminals, a set of terminals corresponding to a specific sub-module of the sub-modules include a power-input terminal arranged to input power from outside the control module. For example, on a printed circuit board (PCB) of the apparatus, arrangement of some modules is similar to that of some contact pads associated to the sets of terminals. In another example, the control module includes a power distribution system including at least one power distribution wire. In another example, a PCB within the apparatus includes at least one signal transmission wire and at least one set of co-plane ground wires.

Abstract: In a memory, the surface temperature and the internal resistance of an assembled battery detected under the condition where a difference between the surface and the internal temperature is within a predetermined value are stored, and an internal temperature diagnosis unit that diagnoses whether or not the internal temperature estimated by an internal temperature estimation unit is correct, detects the internal resistance with an internal resistance calculation unit when the internal temperature estimation unit estimates the internal temperature, searches for an internal resistance corresponding to the surface temperature equal to the estimated internal temperature value from among the stored internal resistances, and diagnoses the estimated internal temperature value based upon the result of comparison of a search result of the internal resistance and the internal resistance detected during internal temperature estimation.

Abstract: A test device includes a transformer, a loop analyzer, and a protection circuit. The protection circuit includes a control unit, a signal acquisition and amplification unit, and an electronic switch. When the loop analyzer outputs a signal, the signal acquisition and amplification unit acquires the signal output from the loop analyzer, amplifies the acquired signal, and outputs the amplified signal to the control unit. The control unit transforms the received signal from analog form to digital form, and compares the digital signal with a reference value. If the digital signal is greater than the reference value, the control unit outputs a control signal to the electronic switch, to turn off the electronic switch. The signal output from the loop analyzer cannot be transmitted to a buck circuit.

Abstract: A direct current-to-direct current (DC-DC) power supply includes a voltage converter module that converts an input voltage having a first voltage level into an output voltage having a second voltage level that is less than the first voltage level. An over-voltage detection module receives the second voltage and generates an over-voltage signal indicating an over-voltage condition of the DC-DC power supply. A shutdown module receives the over-voltage signal and generates a shutdown signal in response to the over-voltage condition. An over-voltage protection module interposed between the shutdown module and the input of the voltage converter module. The over-voltage protection module is configured to selectively inhibit delivery of the input voltage to the voltage converter module in response to the shutdown signal.

Abstract: A buck circuit includes a first inductor, a second inductor, a first capacitor, a second capacitor, a first resistor, a second resistor, a first electronic switch, a second electronic switch, a controller, a voltage input terminal, and a voltage output terminal. The relationship of the capacitance C of the first capacitor, the resistance R of the first resistor, the inductance L of the first inductor, and the equivalent impedance Z of the first inductor is R*C=L/Z. The controller detects voltage of the first capacitor, determines whether current of the first inductor is more than a preset value according to the voltage of the first capacitor, and executes over-current protection when the current of the first inductor is more than the preset value.

Abstract: A circuit for protecting a controllable power switch is provided. The controllable power switch has a first power switch terminal connected to a first terminal, a second power switch terminal connected to a second terminal, and a power switch control terminal. Further, the circuit includes a diode with a first diode terminal and a second diode terminal, and a controllable control switch having a first control switch terminal connected to the first diode terminal, a second control switch terminal, and a control switch control terminal. A signal applied to the power switch control terminal is based on a signal at the second control switch terminal. Further a method for protecting a controllable power switch is described.

Abstract: A direct current-to-direct current converter includes: a buck-boost unit configured to receive an input power source supplied through an input power line, where the buck-boost unit outputs a first power source obtained by boosting the input power source and a second power source obtained by dropping the input power source; and a short-circuit sensing unit connected to the input power line and a control signal line, and configured to sense a short circuit between the input power line and the control signal line, where the short-circuit sensing unit turns off the buck-boost unit when the short circuit between the input power line and the control signal line occurs.

Abstract: Provided is a system and method for detecting and correcting a suboptimal operation of one or more maximum power point tracking (MPPT) devices in a solar photovoltaic power generation (SPVPG) system. MPPT devices may become stuck in a local maximum in a power curve and fail to reach an optimal maximum power point. Described herein are methods and systems for detecting sub-optimal performance of an MPPT device and managing components within the SPVPG system to cause the MPPT device to track a different maximum power point.

Abstract: A method for monitoring an inverter module for a multi-phase electric motor/generator includes deactivating operation of the inverter module, monitoring voltage on a high-voltage bus configured to supply electric power to the inverter module, detecting occurrence of a true fault when a change in the voltage on the high-voltage bus is greater than a predetermined threshold, and detecting occurrence of a false fault when the change in the voltage on the high-voltage bus is less than the predetermined threshold.

Abstract: Disclosed is a power converting apparatus capable of protecting a voltage source converter in the event of a short circuit in a power converting apparatus using a plurality of voltage source converters. The power converting apparatus comprises a semiconductor protection circuit connected in parallel to a converter arm unit including a plurality of voltage source converters, thus enabling overcurrent generated in the event of a short circuit to flow through the semiconductor protection circuit.

Abstract: A safety switching device for switching on or off a hazardous installation in a failsafe manner has a failsafe control/evaluating unit and a power supply for providing at least one operating voltage for the control/evaluating unit. The power supply has a voltage converter for converting an input voltage into an output voltage of a defined output voltage value. The output voltage corresponds to the operating voltage. The power supply has a fault detector for detecting a fault condition of the voltage converter. The fault detector has a comparator for comparing a currently existent output voltage with a defined reference voltage. The fault detector provides a fault condition signal upon detection of a predetermined deviation from the reference voltage. The power supply also has a switch which disconnects the input voltage of the voltage converter when the fault condition signal is present.

Abstract: A short-circuit protection circuit adapted to a voltage regulator module is provided. The voltage regulator module includes a high side transistor and a low side transistor. The short-circuit protection circuit includes a short-circuit detecting circuit, a first switch, and a second switch. The short-circuit detecting circuit includes a detecting terminal coupled with the high side transistor. The high side transistor is connected with the low side transistor and a load, and the low side transistor is coupled with a ground. The first switch is connected with the low side transistor in parallel. The second switch coupled between the high side transistor and the power supply. The first switch is turned on before the power supply is powered on, the short-circuit detecting circuit sends a detecting voltage to the high side transistor via the detecting terminal to determine whether the high side transistor is short-circuited to control to second switch.

Abstract: A power converter includes a voltage conversion unit that provides a first driving voltage at a first output electrode by converting a power supply voltage in response to a first control signal, the voltage conversion unit being configured to provide a second driving voltage at a second output electrode by converting the power supply voltage after a short detection period, the voltage conversion unit being configured to shut down in response to a third control signal, and a short detection unit that generates the third control signal by comparing a magnitude of a voltage of the second output electrode with a magnitude of a reference voltage during the short detection period.

Abstract: An inverter for an electric machine, and a method for operating the inverter, has at least one output stage unit for producing a connection between the electric machine and a power supply network, a control unit for controlling the output stage unit, a supply unit independent of the power supply network for power supply of the output stage unit, at least one emergency operation control assigned to the output stage unit for controlling the output stage unit such that switching elements are switched into a short circuit operation, at least one emergency operation supply assigned to the output stage unit for generating a power supply from the power supply network, and a coordination control, which activates or deactivates the emergency operation control as a function of a status signal of the independent supply unit and a standby signal of the control unit.

Abstract: In a power converter, a driver that drives, according to a control signal, a switching element of a switch circuit for converting input power to output power. The control signal represents how to drive the switching element. A controller outputs the control signal to the driver for controlling the driver. A measuring unit measures a value of input power input to the switch circuit. A protection determining unit determines, based on the measured value of the input power, whether there is a need to protect the power converter. The protection determining unit outputs a stop control signal to at least one of the driver and the controller based on a result of the determination of whether there is a need to protect the power converter. The stop control signal represents whether to forcibly stop drive of the switching element.

Abstract: Monitoring of a core logic internal voltage regulator output is performed to detect, alarm and put an integrated circuit device into a safe mode when the voltage on the core logic exceeds a safe operating voltage value. This allows putting the integrated circuit devise into a predictable, detectable and safe mode, and to alarm the over-voltage condition to a system monitor to alert on a fault and subsequent fault disposition.

Abstract: A surge protection circuit, a switching power supply, and a surge protection method are provided that can prevent a power supply from being damaged by a high energy surge voltage discharged from a terminal device to an output end of a power supply. The surge protection circuit is applied to the switching power supply. The power supply includes a transformer. The circuit includes a surge protection tube. When a surge voltage on the terminal device is greater than a discharge voltage of the surge protection tube, the surge protection tube is conducted and discharges the surge voltage on the terminal device to the ground wire end at the high voltage side of the transformer. The embodiments of the present invention are applicable to the field of electronic technologies.

Abstract: A photovoltaic array for use in an electrical power system includes multiple photovoltaic modules and a voltage converter coupled to at least one of the photovoltaic modules. The photovoltaic array also includes an over-voltage protection circuit. The over-voltage protection circuit includes an interface adapted to couple to an output of the voltage converter. The over-voltage protection circuit also includes a spike detector configured to detect a voltage spike in an output voltage of the voltage converter. The over-voltage protection circuit further includes a voltage control module configured to regulate an output voltage slew rate of the voltage converter in response to an over-voltage signal received from the spike detector.

Abstract: An electronic device comprising a Printed Circuit Board (PCB), a battery for supplying power to the PCB and at least one moisture detection sheet mounted on the PCB and the PCB shuts off power from the battery in response to detected electrical current conduction via the at least one moisture detection sheet.

Abstract: A protection circuit of a DC-DC converter is disclosed. An input terminal of the DC-DC converter receives an input voltage and an output terminal of the DC-DC converter provides an output voltage. The DC-DC converter includes an output stage between the input terminal and the output terminal. The protection circuit includes a current sensor, a comparator, a determining circuit, and a protection control circuit. The current sensor provides a sensing signal. The comparator compares a default over-voltage with the sensing signal to provide an over-current control signal. The determining circuit provides a determining control signal. The protection control circuit determines whether to enable a short protection according to the over-current control signal and the determining control signal.

Abstract: The invention relates to a circuit arrangement (10) for a control device, and a method for operating said circuit arrangement (10). The circuit arrangement (10) comprises a first field-effect transistor (12) actuating the control device, and a comparator, which compares the voltage provided for actuating the control device with a threshold voltage, and which actuates a timed operation of the first field-effect transistor (12) via a control unit (20) if the threshold voltage is exceeded.

Abstract: A switching regulator includes a power stage for coupling to a load through an inductor. The power stage switches so that the power stage sources positive current to the load through a first transistor of the power stage during some periods and sinks negative current from the load through a second transistor of the power stage during other periods. The switching regulator further includes a protection circuit operable to force the second transistor into an off-state state responsive to the negative current flowing through the inductor exceeding a predetermined negative threshold.

Abstract: A control means comprises a control segment (3) that is designed for driving an electrically adjustable piece of furniture and a switched-mode power supply unit (2) that supplies power to the control segment (3). The switched-mode power supply unit (2) features a switching regulator component (223) for controlling the switched-mode power supply unit and can be switched into a normal operating mode and into an idle mode. The switched-mode power supply unit (2) is designed for making available a supply voltage for the switching regulator component (223) in a clocked fashion with the aid of a start-up circuit (224) in the idle mode. The switched-mode power supply unit (2) features a power failure detection circuit (230) that is designed for detecting a failure of a line voltage applied to the input side of the switched-mode power supply unit (2) based on a signal within the start-up circuit (224) and for signaling this failure to the control segment (3).

Abstract: Power supply circuit comprises an under voltage protection unit and a voltage conversion unit electrically connected to the under voltage protection unit. The under voltage protection unit comprises a control chip, an npn-type bipolar junction transistor (BJT), a pnp-type BJT, and first fourth resistors. The under voltage protection unit and the voltage conversion unit are electrically connected to a power supply. When a voltage of the power supply is in a normal range, the under voltage protection unit outputs a first control signal to the voltage conversion unit. The voltage conversion unit converts the voltage of the power supply into an operation voltage, and outputs the operation voltage. When the voltage of the power supply is less than a threshold voltage, the under voltage protection unit outputs a second control signal to the voltage conversion unit, and the voltage conversion unit does not operate.

Abstract: Embodiments of the present invention relate to a switch control circuit, a switch control method, and a power supply device using the same. Embodiments generate a reference signal according to a full-wave rectification voltage and control a switching operation of a power switch according to a comparing result of a sense voltage corresponding to a current flowing to the power switch and the reference voltage. Embodiments determine whether a line is opened between a first output terminal and a second output terminal of the power supply device using the sense voltage. When the line is opened, Embodiments turn off the protection switch.

Abstract: Voltage protection circuit connected between a current protection circuit and a load. The voltage protection circuit includes a comparator, an inverter, and an electronic switch. The current protection circuit is connected between the load and a power supply circuit for protecting the load from over-current. When an output voltage of the power supply circuit is less than a rated voltage of the load, the load receives the output voltage of the power supply circuit as normal. The power supply circuit stops outputting the output voltage to the load for protection, when the output voltage of the power supply circuit is greater than the rated voltage of the load.

Abstract: A microcomputer is equipped with a CPU and an AD converter. The AD converter is supplied with the same power source voltage as the CPU, and converts a reference voltage into digital data using the received power source voltage and outputs the digital data as a conversion value. The CPU detects a state of the power source voltage by calculating a voltage variation of a power source voltage for ordinary operation on the basis of a first conversion value obtained by AD-converting the reference voltage by the AD converter in a state that a standard power source voltage including no voltage variation is supplied to the AD converter and a second conversion value obtained by AD-converting the reference voltage by the AD converter in a state that the power source voltage for ordinary operation is supplied to the AD converter.

Abstract: The present invention discloses an overcurrent protection circuit for a light source driving module and a related backlight module. The overcurrent protection circuit includes an average value overcurrent protection circuit for detecting an average voltage at a node where the switch is connected to the detection resistor and generating the turning-off signal to turn off the switch when the average voltage is larger or equal to a threshold average voltage, wherein the average voltage is formed by an average current of the switch. Through the above-mentioned mechanism, the present invention can prevent the working power of a power device from being larger than its rated power. Therefore, it also prevents the power device from catching a fire due to a potential high temperature.

Abstract: An overvoltage protection circuit includes a first connector connected to an alternating current (AC) power source, a second connector connected to an electronic device, an alternating current to direct current (AC/DC) rectifying circuit, a voltage regulating diode, a relay, a first electronic switch, and a second electronic switch. The first connector is connected to the AC/DC rectifying circuit. The AC/DC rectifying circuit is connected to the first electronic switch through the voltage regulating diode. The first electronic switch is connected to the second electronic switch. The second electronic switch is connected to the relay. The first connector is connected to the second connector through the relay.

Abstract: In one general aspect, an apparatus can include an overcurrent protection device. The apparatus can include an overvoltage protection device coupled to the overcurrent protection device and configured to cause the overcurrent protection device to decrease a current through the overvoltage protection device after a breakdown voltage of the overvoltage protection device increases in response to heat.